Floating scarecrow and bird-of-prey kite cut seabird deaths in fishing nets by two thirds

Every winter, off the rugged coast of Cornwall, thousands of diving seabirds plunge beneath the surface of the sea in pursuit of small fish, and some of them never come back up. Beneath the waves, invisible walls of nearly transparent gillnet hang in the water column, and for birds such as guillemots and razorbills, an accidental collision with this gear is usually fatal. A new study published in the journal Conservation Letters now offers the strongest evidence yet that a pair of remarkably simple devices, one of them described as a floating scarecrow, can slash these deaths by around two thirds, offering fresh hope for some of Europe’s most threatened seabird populations.

The scale of the problem is sobering. Researchers estimate that around 95,000 diving seabirds are incidentally caught and drowned in gillnets around the coast of Europe every year. The phenomenon, known as bycatch, is one of the most pressing yet least visible threats facing marine wildlife globally, affecting a wide range of seabird species well beyond European waters. Unlike seabirds killed in trawl or longline fisheries, where mitigation tools such as bird-scaring lines have already delivered dramatic reductions in mortality, gillnets have long proved stubbornly resistant to practical solutions. The gear operates silently and largely unseen, and any device deployed to protect birds must survive harsh conditions at sea while never interfering with the fishers’ ability to work.

That challenge is precisely what motivated an eight-year collaboration between scientists at Fishtek Marine, a Devon-based company and global leader in marine conservation technology, and the RSPB, the UK’s nature conservation charity. The fruit of that partnership is the Looming Eye Buoy, or LEB, a floating deterrent with a deceptively simple design philosophy. The buoy carries a spinning head that creates an animated eye effect on the water surface. To a diving bird approaching from the air, the looming eye mimics the gaze of a potential predator, triggering an instinctive avoidance response that steers the bird away from the patch of water where a gillnet is set. The concept draws on well-established principles of predator recognition in birds, in which large eye-like patterns reliably provoke escape behaviour across many species.

The research team did not rely on a single design. Alongside the LEB, they trialled an alternative deterrent built from a commercially available kite shaped like a bird of prey, known as the scarybird kite. Towed or flown above the fishing operation, the kite presents the silhouette and movement of a raptor, exploiting the same evolutionary wariness that keeps small birds alert to overhead predators. Testing two distinct approaches, one visual lure anchored at the surface and one aerial mimic, allowed the scientists to compare how different deterrent strategies performed under real commercial fishing conditions rather than in idealised experimental settings.

The trials themselves were a model of industry-science collaboration. Over two years, ten Cornish fishermen fitted cameras to their boats and collected data on how the devices affected seabird bycatch during normal fishing operations. This onboard monitoring was essential, because bycatch is rare and patchy enough that reliable measurement demands sustained observation across many fishing events. The resulting dataset was analysed by scientists at the University of Exeter, who quantified the reduction in risk for the two species most frequently caught in the region’s gillnet fishery: guillemots and razorbills, both members of the auk family that pursue fish underwater using their wings.

The results were striking. Both devices decreased the risk of guillemots and razorbills being caught in nets by roughly two thirds. Specifically, the chances of a bird being caught fell by 59 percent when Looming Eye Buoys were deployed and by 71 percent when the scarybird kites were used. For a conservation problem that has resisted mitigation for decades, reductions of this magnitude from inexpensive, low-tech floating deterrents represent a genuine breakthrough. Crucially, the devices achieved these gains without halting fishing, meaning that livelihoods and conservation goals could advance together rather than in conflict.

Perhaps even more valuable than the headline reduction figures was a second discovery buried in the data: bycatch in Cornwall is intensely seasonal. The analysis showed that most seabirds were caught during the winter months, when auks gather in large numbers in Cornish waters. This pattern transforms the economics and logistics of protection. Rather than requiring deterrents on every gillnet vessel year-round, conservation effort can be concentrated in the seasons and locations where risk peaks, making deployments targeted, efficient and far cheaper. Tom Horton, lead author from the University of Exeter, said the study provides some of the strongest evidence to date that simple, practical deterrents can substantially reduce seabird bycatch in gillnet fisheries, and that by identifying when and where bycatch risk is highest, there is now a clear opportunity to target mitigation measures where they deliver the greatest conservation benefit for vulnerable seabird populations while encouraging sustainable fishing practices.

Tom Hooper, senior fisheries scientist at Fishtek Marine, emphasised that the trials showed floating deterrents can make a real difference in protecting seabirds from getting caught in fishing gear, and that one of the most significant results was demonstrating how bycatch concentrates in key locations at specific times of year, allowing deterrent efforts to be directed and efficient. He also stressed a practical truth of working at sea: any technology deployed on fishing boats must be simple and robust. Working hand in hand with fishermen, he noted, taught the team a great deal about how the devices were actually used, enabling refinements that fit the operational needs of the crews who must handle the gear in rough weather and tight schedules. Pete Kibel, co-founder and director of Fishtek Marine, added that the collaboration with the fishing industry, the RSPB and the University of Exeter will continue with the aim of further improving the devices’ efficiency.

The fishermen themselves emerged as enthusiastic partners rather than reluctant subjects. Micky Bacon, a fisherman from Mousehole in Cornwall who took part in the trials, said he became involved because the sea is his workplace and it is important that fishermen participate in projects that can affect how they work and help improve the environment. He added that the trial was a good opportunity to show people outside the industry that fishermen do not just want to catch fish, but also want to be part and parcel of improving the environment. That goodwill matters, because the long-term success of any bycatch mitigation ultimately depends on the crews who must deploy the gear day after day.

The study also builds on a remarkable international track record. The RSPB, as host of the BirdLife International Marine Programme, has been instrumental in deploying bird-scaring lines around the world, an approach that has reduced seabird bycatch by 98 percent in Namibian longline fisheries and by 95 percent in South African trawl fisheries. Yann Rouxel, Bycatch Programme Manager at the RSPB, said that after more than a decade of research into gillnet bycatch and its solutions, it is rewarding to see the work moving towards real-world implementation, noting that while existing technology has cut seabird deaths in trawl and longline fisheries by over 90 percent, gillnets have proved a real challenge and pose a significant threat to seabirds in the UK. He described the performance of the LEB and the kite as a major milestone in reducing bycatch without impeding gillnet fishers while at sea. The latest study was funded by the Defra Fishing Industry Science Partnership programme and Schmidt Marine Technology Partners, and with winter deployments now guided by hard data, the floating scarecrow and its raptor-shaped rival may soon become standard kit on gillnet boats, turning a decades-old conservation deadlock into one of the most encouraging seabird success stories in years.

Subject of Research: Testing floating visual deterrents to reduce seabird bycatch in gillnet fisheries

Article Title: Scientists develop ‘floating scarecrow’ to protect threatened seabirds

Article References: Scientists develop ‘floating scarecrow’ to protect threatened seabirds. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: seabird bycatch, gillnet fisheries, Looming Eye Buoy, guillemots, razorbills, Cornwall, Fishtek Marine, RSPB, University of Exeter, Conservation Letters, marine conservation, fishing technology